You should have had your PCT ready prior to starting the cycle.
Sustain / Unleashed / Post-cycle - All great PCT products that I'm sure are in stock at various stores.
The rule of thumb is 'time on = time off'. In other words, if your cycle was 8 weeks, then don't start another one until 8 weeks after you finished. But this is an estimate. You should be starting based only on the results of blood work.